| Hellenic Space Center | Attica |
| Hellenic Technology of Robotics | |
| Hellenic Telecommunications and Post Commission | Attica |
| Help S.A. | |
| Hostdog | Attica |
| Hosthub | Attica |
| Hostivate | Central Macedonia |
| Hostmein Cloud Hosting | |
| Hostsun | Crete |
| Hotel SEO Agency | |
| HotelCrux | Attica |
| Hyper Center | Attica |
| Hyper Hosting | Attica |
| Hypersystems | |
| Hypertech IT Solutions | Attica |
| i-DOCS | Attica |
| I.S.T. - Information Systems Technology Ltd | Attica |
| i4G | |
| iArk Boutique Digital Agency | |
| Iarts | Attica |
| ICAP CRIF | Attica |
| ICBS Business College | |
| IdEF College | |
| IDSS | |
| iFORM Information Technologies | |
| iforU | |
| iGROUP Πληροφορική Ε.Π.Ε. | Attica |
| iGuRu Νέα | Attica |
| IMBnet | |
| Impression eStudio | Attica |
| Independent Science and Technology College | |
| Indev Software | |
| Industrial Systems Institute | |
| Industry Disruptors | Attica |
| Infitiny | Attica |
| Info Quest Technologies SA | |
| Infolex S.A. | Attica |
| Informal Advertising Ltd | |
| Information Systems Impact | Attica |
| Information Technologies Institute | |
| InfoSoft net | Central Greece |
| InnovAthens | |
| Innovative Technologies Centre S.A. | |
| Innovis S.A. | |
| Insoft.gr | Attica |
| Institute for Language and Speech Processing | |
| Institute of Accelerating Systems and Applications | |
| Institute of Electronic Structure & Laser | |
| Intale | |
| Integrated Information Systems | Attica |